While poring through the collection of over 130,000 exhibits They reported the “surprise discovery” in a press release According to the correspondence from 1949 between Braunkohlenbergbau Maxhütte AG - Zeche Mathias near Schwandorf and the Bavarian Geological State Office (GLA) the coal miner who wrote this letter stated that there was “humboldtine” mineral somewhere in the Mathiaszeche According to LfU humboldtine is a rare organic mineral found only in about 30 locations worldwide including the rhyolite quarries in the Spessart in Bavaria to talk about finding this rare mineral in Mathiaszeche humboldtine has only been found as tiny crystals in a few places around the world It was only the in-house laboratory analysis that provided certainty,” Eichhorn said the agency started a search and eventually found the evidence of what was written in the letter in their Geological Service's rock collection In one of the drawers cataloged as rare organic minerals the employees found “two boxes of cm-sized yellowish chunks.” The labels attached indicated that it was indeed humboldtine in these boxes Further investigation of the crystal’s mineralogical composition using a powder X-ray diffractometer confirmed that it was humboldtine Humboldtine’s structure is composed of carbon, water, and iron, which give it its characteristic yellow color. LfU described that there is a brown coal mining site to the northwest of Schwandorf (Upper Palatinate), between Irlbach and Sitzenhof. Mining started on the site in the summer of 1945 but had to be ceased in 1966 due to a massive flood, Forbes says Brown coal mining was discontinued and the open-pit mine is not recultivated and used as a landfill So even after coming too close to the source of one of the rarest minerals on Earth the possibility of actually mining it will forever remain a mystery A post shared by Munich Show - Mineralientage München (@the_munich_show) “A rediscovered legendary and once-in-a-lifetime piece,” she wrote on Instagram A post shared by Andi (@abcmineralien)